z86c9216vsc ZiLOG Semiconductor, z86c9216vsc Datasheet - Page 26

• Manufacturer Part Number: z86c9216vsc
• Description: Ir Microcontroller
• Manufacturer: ZiLOG Semiconductor

PIN FUNCTIONS (Continued)
Z86C72/C92/L72/L92
IR Microcontroller
Port 3 (P37-P31). Port 3 is a 7-bit, CMOS compatible three
fixed input and four fixed output port. Port 3 consists of
three fixed input (P33-P31) and four fixed output (P37-
P34), and can be configured under software control for In-
put/Output, Interrupt, Port handshake, Data Memory func-
tions and output from the counter/timers. P31, P32, and
P33 are standard CMOS inputs; outputs are push-pull.
Two on-board comparators process analog signals on P31
and P32 with reference to the voltage on Pref1 and P33.
The analog function is enabled by programming the Port 3
Mode Register (bit 1). P31 and P32 are programmable as
rising, falling, or both edge triggered interrupts (IRQ regis-
Notes:
HS = Handshake Signals
D = /DAV
R = RDY
6-26
Pref1
P31
P32
P33
P34
P35
P36
P37
P20
Pin
OUT
OUT
OUT
OUT
I/O
I/O
IN
IN
IN
IN
T8/16
T16
C/T
T8
IN
IN
Comp.
RF1
AN1
AN2
RF2
A01
A02
Table 2. Pin Assignments
IRQ2
IRQ0
IRQ1
Int.
P R E L I M I N A R Y
P0 HS
D/R
R/D
ter bits 6 and 7). Pref1 and P33 are the comparator refer-
ence voltage inputs. Access to the Counter Timer edge de-
tection circuit is through P31 or P20 (see CTR1
description).
Port 3 provides the following control functions: handshake
for Ports 0, 1, and 2 (/DAV and RDY); three external inter-
rupt request signals (IRQ2-IRQ0); Data Memory Select
(/DM) (Table 2).
Port 3 also provides output for each of the counter/timers
and the AND/OR Logic. Control is performed by program-
ming bits D5-D4 of CTRI, bit 0 of CTR0 and bit 0 of CTR2.
P1 HS
D/R
R/D
P2 HS
D/R
R/D
DS97LVO0900
Ext
DM
Zilog